Is my tivo dead?

So it would seem that I have troubles. My tivo doesn't do much these days. But it does do some things. Here's what it does do:

• Hard drive spins up
• Seems like I'm getting the right voltages from the power supply (which I did try replacing already, though the new one could be bad too)
• Backlight comes on behind the directional buttons

Here's what it doesn't do:

• There is nothing displayed at all on the front lcd
• There is no video output
• The pins powering the fan are not keeping a steady voltage, it's oscillating between 12V and 0V fairly quickly.

Please tell me that I bought a defective power supply and can return it. Otherwise, this will be expensive.